diff --git a/frigate/config.py b/frigate/config.py
index 48e785c53b..a321594e6e 100644
--- a/frigate/config.py
+++ b/frigate/config.py
@@ -44,6 +44,7 @@
 
 DEFAULT_TRACKED_OBJECTS = ["person"]
 DEFAULT_DETECTORS = {"cpu": {"type": "cpu"}}
+DEFAULT_DETECT_DIMENSIONS = {"width": 1280, "height": 720}
 
 
 class FrigateBaseModel(BaseModel):
@@ -268,8 +269,14 @@ class StationaryConfig(FrigateBaseModel):
 
 class DetectConfig(FrigateBaseModel):
     autoconf: bool = Field(default=True, title="Auto detect height, width and fps.")
-    height: int = Field(default=720, title="Height of the stream for the detect role.")
-    width: int = Field(default=1280, title="Width of the stream for the detect role.")
+    height: int = Field(
+        default=DEFAULT_DETECT_DIMENSIONS["height"],
+        title="Height of the stream for the detect role.",
+    )
+    width: int = Field(
+        default=DEFAULT_DETECT_DIMENSIONS["width"],
+        title="Width of the stream for the detect role.",
+    )
     fps: int = Field(
         default=5, title="Number of frames per second to process through detection."
     )
@@ -672,8 +679,19 @@ def __init__(self, **config):
                 config["ffmpeg"]["inputs"][0]["roles"].append("rtmp")
 
         for input in config["ffmpeg"]["inputs"]:
-            if config["detect"].get("autoconf") and (
-                "detect" in input.get("roles", [])
+            if (
+                config["detect"].get("autoconf")
+                and ("detect" in input.get("roles", []))
+                and (
+                    config["detect"].get("height") is None
+                    or config["detect"].get("width") is None
+                    or (
+                        config["detect"].get("height")
+                        == DEFAULT_DETECT_DIMENSIONS["height"]
+                        and config["detect"].get("width")
+                        == DEFAULT_DETECT_DIMENSIONS["width"]
+                    )
+                )
             ):
                 try:
                     streamInfo = get_video_properties(input.get("path"))